mac80211: stop toggling IEEE80211_HT_CAP_SUP_WIDTH_20_40

For VHT, many more bandwidth changes are possible. As a first
step, stop toggling the IEEE80211_HT_CAP_SUP_WIDTH_20_40 flag
in the HT capabilities and instead introduce a bandwidth field
indicating the currently usable bandwidth to transmit to the
station. Of course, make all drivers use it.

To achieve this, make ieee80211_ht_cap_ie_to_sta_ht_cap() get
the station as an argument, rather than the new capabilities,
so it can set up the new bandwidth field.

If the station is a VHT station and VHT bandwidth is in use,
also set the bandwidth accordingly.

Doing this allows us to get rid of the supports_40mhz flag as
the HT capabilities now reflect the true capability instead of
the current setting.

While at it, also fix ieee80211_ht_cap_ie_to_sta_ht_cap() to not
ignore HT cap overrides when MCS TX isn't supported (not that it
really happens...)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 5 insertions, 19 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/rs.c b/drivers/net/wireless/iwlwifi/mvm/rs.c
index 60a4291ca22..8ba36e5e4b6 100644
--- a/drivers/net/wireless/iwlwifi/mvm/rs.c
+++ b/drivers/net/wireless/iwlwifi/mvm/rs.c
@@ -1209,23 +1209,9 @@ static s32 rs_get_best_rate(struct iwl_mvm *mvm,
 	return new_rate;
 }
 
-static bool iwl_is_ht40_tx_allowed(struct iwl_mvm *mvm,
-			    struct ieee80211_sta_ht_cap *ht_cap)
+static bool iwl_is_ht40_tx_allowed(struct ieee80211_sta *sta)
 {
-	/*
-	 * Remainder of this function checks ht_cap, but if it's
-	 * NULL then we can do HT40 (special case for RXON)
-	 */
-	if (!ht_cap)
-		return true;
-
-	if (!ht_cap->ht_supported)
-		return false;
-
-	if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40))
-		return false;
-
-	return true;
+	return sta->bandwidth >= IEEE80211_STA_RX_BW_40;
 }
 
 /*
@@ -1258,7 +1244,7 @@ static int rs_switch_to_mimo2(struct iwl_mvm *mvm,
 	tbl->max_search = IWL_MAX_SEARCH;
 	rate_mask = lq_sta->active_mimo2_rate;
 
-	if (iwl_is_ht40_tx_allowed(mvm, &sta->ht_cap))
+	if (iwl_is_ht40_tx_allowed(sta))
 		tbl->is_ht40 = 1;
 	else
 		tbl->is_ht40 = 0;
@@ -1311,7 +1297,7 @@ static int rs_switch_to_mimo3(struct iwl_mvm *mvm,
 	tbl->max_search = IWL_MAX_11N_MIMO3_SEARCH;
 	rate_mask = lq_sta->active_mimo3_rate;
 
-	if (iwl_is_ht40_tx_allowed(mvm, &sta->ht_cap))
+	if (iwl_is_ht40_tx_allowed(sta))
 		tbl->is_ht40 = 1;
 	else
 		tbl->is_ht40 = 0;
@@ -1356,7 +1342,7 @@ static int rs_switch_to_siso(struct iwl_mvm *mvm,
 	tbl->max_search = IWL_MAX_SEARCH;
 	rate_mask = lq_sta->active_siso_rate;
 
-	if (iwl_is_ht40_tx_allowed(mvm, &sta->ht_cap))
+	if (iwl_is_ht40_tx_allowed(sta))
 		tbl->is_ht40 = 1;
 	else
 		tbl->is_ht40 = 0;